Roasting-furnace.



PATENTED JULY 4, 1905.

P. ELEPETKO.

ROASTING FURNACE.

APPLIOATION FILED OUT. 22,190a.

2 SHEETSSHBET 1.

aflioznu l vihlcas s No. 793,939. PATENTED JULY 4-, 1905. 1 1-. KLEPETKO.

ROASTING FURNACE.

APPLICATION FILED OUT. 22,1904.

2 SHEETSSHEET 2 u. trusses.

Ill?"aten.ted Ql'uly 1, 190b,

tllrricle,

FRANK Kliltllt' TKO, OF NEW YUl-tK, N. "i".

li itlln i ll' ll l il l ltll l t W! at; lEEI fSPlECIFIOAElJION forming part of Letters Patent lil'o. "193,9?9, dated July 1, 1905.

llpplimttion filed October 22, 1904:. Serial iflo. 2519.633.

7b (11/7 10/1/0171, if; may (EON/("15170:

lie it known that l, l nauu Knnrnrruo, a citizen ol the Unitet States, residing at New l'ork, in the county of New York and State cl blew York, have invented certain new and useful improvements in ltoasting-burnaces, ol which the lollowii'igis a full, clear, and ex act description, reference being bad to the aecompanying drawings, forming a part hereol.

l /l y invention has relation to img'novements in roasting-lurnaces; and it consists in the novel arrangement and combinatioi'i oi parts more fully set lorth in the specilication and pointed out in the claim.

in the d rawii'igs, Figurel isa combined elevation and section of a conventioi'ial McDongall ore-roasting furnace, SllOWll'lg' one Form 0] my invention applied thereto. Fig. 9. is a horizonal section on line 52 2 of Fig. 1, taken through the upper hearth. Fig. 3 is a top plan 01 a rabble-arm, showin a modified form of rake covered by the present invention. Fig. 4 is a side elevation thereof. Fig. 5 is a top plan of a rabble-arm, shown 7 the rakes disposed at different angles to e .ect the re sults contemplated by my invention; and Fig. 6 is a side elevation of the same.

The present invention is directed to the raking mechanism oi. ore-roasting (or other) furnaces wherein the material is raked toward the center of one hearth, where it isdisclnn'ged onto the hearth beneath, where in turn it is raked radially outward to be dis charged through marginal openings onto the next or third hearth, and so on till it reaches the bottom hearth. A cmlventirjnml type oi such a 'l'urnace is the M cl )ongall. (illustrated in the drawil'igs.) For the treatment of ore. which require a comparatively long exposure to the heat and where it is desirable to allow the ore to remain a cm'respondiugly longer time on the hearth it C(JUllUlIllUfll to materially increase the dian'ieter of the l'urnace to secure an increased area for the hearth. (living to this increase in area and the increased. capacity of any hearth, the ore accumulating at the center under the action of the rakes must be disposed of as fast as it accumulates. It the rakes carried by the rabble-arms were all of one size or were so disposed angnlarly as to have the same area oi? radially-el'lfective leed, the ore would pile up at the center and the hearth become choked up. To avoid this consequence, I provide each rabble-arm with a series of rakes whose radially-ellective sweepingsurlace increases toward the center of the hearth, all as will more Fully appear from a detailed description of the invention, which is as l'ollows.

l-telerring to the drawings, and mrtienlarly Figs. 1. and 2, l1 rean'esents the 'lurnace, and it the hearths in which the material is treated, the latter dropping from the upper hearth si'lccessivcly through the several hearths until it is received by the ilelivory-hopper "U, the

hearths being provided, respectively, with the central and marginal (awnings 1. 2 for the passage of the material. Passing through the hearths is the rotatable rabble-shaft 3, from which radiate the series oi rabble-arms 4, extending into the several hearths and carrying rakes or rabbles 5, by which the material is successively fed from one hearth to the hearth immediately beneath, all as fully understood in the art. Taking the upper hearth as an example, we can for convenience divide the same into two areas, an outer annular area a and an inner annular area. 11,, Fig. 2. With the rabble arms and shaft rotating in the direction indicated by the arrow, the rakes will feed the ore radially toward the central open ing 1; but owing to the quantity ol ore treated on a hearth ol il'lcreased capacity the ore thus raked toward the center will pile up as it approaches the opening 1, the material distributed over the area a being obliged to occupy the dimiiiiished area a. 'lhe ore thus piled up (see dotted wave line in Fig. l, which represents the character of pile 'l'ornied) unless taken care o l and raked in to the l iscbargeopening 1 would accumulate and choke up the hearth, so that to avoid such mnseiplence l increase the superlicial area of the rakes as they approach the center of the furnace, the increase in the area oil the rakes thereby olfering a larger rakingsurlace to the ore thus accumulated. l may (lor blades whose angle of deflection is uniform for the full length. of the rabifle-arm) increase this rakmg-snrlace by either increasing the depths ol the blades approaching the center, as shown in Fig. 1, or 1 may increase the width of the blades, as shown by blades 5 in Figs. 3 and 4, or I may increase both the depth and width. By raking-surface is herein meant that component of the entire area of the blade which is available for driving the ore radially, (inward or outward,) for it must be remembered that at the same time the ore is rated toward or from the center of the hearth it is constantly being raked circularly. The circular travel of the ore, however, is in no wise instrumental in producing the piling up thereof, as described, but it is only the radial advance of the ore inardl y to which the piling up is directly due. It must be remembered that the blades are dei' icted to the proper angle to etiecta radial fulvance in either direction and that by varying the angle of deflection as to some of the blades we can increase that component of the blades area which is available to direct the ore radially, so that, as shown in Figs. 5 and 6, the outer blades 5", which are set at a less acute angle of deflection (relatively to the axis of the rabble-arm) than the inner blades, will have a less tendency to rake the ore radially tl Ian the inner blades, which are set at a greater inclination to the axis of the rabble-arm. The results accomplished, therefore, by the disposition of the blades as shown in the modification in Figs. 5 and 6 are the same as those shown in Figs. 1 to a, inclusive. 1 may even qualify the arrai'igement shown in Figs. 5 and b by increasing the areas of the inner blades by the methods proposed in connection with Figs. '1 to l, inclusive. Of course what is true for the top hearth is true for the second hearth. In the latter the ore accumulated at the center must be raked radially outward; but as it approaches the area (7/ the necessity for its rapid radial advance becomes less pressing, and the availableradially-outward-rahing surfaces of the respective blades decreases as they approach the outer ends of the rabblearms. \Ve may consider that the ore travels along each hearth in two directions a circular direction and a radial direction. Of course it is only the radial direction with which the present invention is concerned, since the circular component is a dead element so far as its tendency to pile up the ore at the center is concerned. Generically expressed, therefore, my invention contemplates providing a rabble-arm with rakes whose available radially-feeding surface increases toward the inner end of the arm or toward the end at which accumulation of the ore tends. This surface is that component of the entire surface which drives the ore radially, the other component driving it circularly. This component (the radial one) may be varied or increased by either of the methods above outlined or by any combination of them. \Vcre it not for the arrangement here disclosed the ore in furnaces of large hearth capacity would simply pile up over the rabble-arm and choke the hearth.

The generic idea here set forth may of course be used in other connections or arts and need not be limited in its application to roastingfurnaces.

llaving described my invention, what I claim is- A rabble-arm adapted to rotate about a fixed axis, having a series of rakes whose depth increase as they approach said axis, substantially as set forth.

In testimony whereof I ailix my signature in presence of two witnesses.

FRANK KLEPIETKO.

\Vitnesses:

(Inns. V. Dnnw, M. PESTANA. 

